Natural and Mathematical Sciences Departments

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Open Access
Further screening of Venda medicinal plants for activity against HIV type 1 reverse transcriptase and integrase
(2006-03-15) Bessong, Pascal O.; Rojas, Luis B; Obi, Larry C.; Tshisikhawe, Peter M.; Igunbor, Eunice O.
The use of medicinal plants for AIDS-related conditions is common in South Africa. In order to establish an antiviral rationale for the use of these plants we screened fractions of the methanol extracts of medicinal plants for activity against HIV-1 reverse transcriptase (RT) and integrase (IN). The n-butanol fraction obtained from the crude methanol extracts of the roots of Bridelia micrantha (Hochst) Baill. (Euphorbiaceae) was observed to be as the most active inhibiting the RNA-dependent-DNA polymerization (RDDP) activity of HIV-1 RT with an IC50 of 7.3 g/ml. However, it had no activity on the 3’-end processing activity of HIV integrase. Bioassay-guided fractionation of the n-butanol fraction yielded friedelin and -sistosterol, which did not inhibit the RDDP of RT or 3’-end processing functions of IN even at a concentration of 500 M. An uncharacterized fraction obtained in the bioassay-guided fractionating process inhibited the RDDP with an IC50 of 9.6 g/ml, but had no inhibition on IN. Phytochemical screening indicated the presence of flavonoids and tannins in the uncharacterized fraction.
Open Access
Drug Resistance Mutations in Naive HIV-1 South African Patients, and Construction of Molecular Clones to Phenotype Putative Resistance Mutations
(2009-03) Mavhandu, Lufuno Grace; Bessong, P. O.; Rekosh, David; Hammarskjold, Marie-Louise
See the attached abstract below
Open Access
In-vitro bioactivity of fractions from a local medicinal plant on HIV-1 replication, and selected fungal and bacterial pathogens
(2009-03) Mutshembele, Awelani Mirinda; Bessong, Pascal O.; Eloff, Jacobus N.; Obi, Larry
See the attached abstract below.
Open Access
q- Enumeration of permutations avoiding adjacent patterns
(2009-09) Takalani, Ntendeni Annah; Tshifhumulo, T. A.
See the attached abstract below
Open Access
Detection of Cryptosporidium species in stools of HIV/AIDS patients in Bela-Bela, South Africa
(2010-06) Makuwa, Stenly Modupi; Bessong, P. O.; Samie, A.; Potgieter, N.
See the attached abstract below
Open Access
Mapping ecological zones in the Kruger National Park using remote sensing
(2010-08) Ratshibvumo, Thihanedzwi; Munyati, C.; Ogola, J. S.
See the attached abstract below
Open Access
The population ecology of Securidaca longepedunculata Fresen. in the Nylsvley Nature Reserve, Limpopo Province, South Africa
(Fyton, 2012) Tshisikhawe, M. P.; Baloyi, O.; Ligavha-Mbelengwa, M. H.; Bhat, R. B.
Securidaca longepedunculata Fresen., commonly known as the violet tree, belongs to the family Polygalaceae. It is widely distributed in tropical Africa, Mozambique, as well as in the North- West and Limpopo provinces of South Africa. The Vhavenda people use the roots of this species as an aphrodisiac. The species is co-dominant in the savanna vegetation of the Nylsvley Nature Reserve. This research looked at the ecology of the study species within the Nylsvley Nature Reserve because of its importance there. Understanding the population structure and environmental factors that impact on the species might help in assessing the population in urban areas. The population of the study species in the reserve displayed an adequate growth curve, when looking at its stem circumference and height-size classes. High intensity fires showed a negative effect on individuals of S. longepedunculata. Evidence of animals feeding on the roots at the study species was also recorded in the study.
Open Access
Flood Frequency Analysis of Annual Maximum Stream Flows for Luvuvhu River Catchment, Limpopo Province, South Africa
(2012) Singo, L. R.; Kundu, P. M.; Odiyo, J. O.; Mathivha, F. I.; Nkuna, T. R.
Luvuvhu River Catchment (LRC) is one of the regions in South Africa where floods have caused enormous damage and impacted negatively on fauna and flora. Over the years, the catchment has experienced floods resulting from heavy rainfall associated with the ITCZ. Annual maximum flow data from 8 stations with 50 years hydrological data were used to analyze flood frequencies in the catchment. To derive the probability of occurrence of flood events, the frequency distributions which could best describe the past characteristics and magnitudes of such floods were tested. This involved the determination of the best flood frequency models, which could be fitted to the available historical recorded data. The distribution models used included the Generalized Extreme Value, Gumbel or Extreme Value type 1, Log-Normal and the Log Pearson type III distributions. The extreme value analysis showed that the Gumbel and Log Pearson type III distributions provided the best fit.
Open Access
Invasive alien plant species: A case study of their use in the Thulamela Local Municipality, Limpopo Province, South Africa
(Academic Journals, 2012-07-19) Semenya, Sebua S.; Tshisikhawe, Milingoni P.; Potgieter, Martin T.
The spread of plants from one country to another through intentional and unintentional human activities is a serious threat to the world’s biodiversity; second only to habitat destruction. However, a number of studies have shown that invasive alien plant species can positively contribute to rural economies. This paper is an attempt to document a few of these species ‘positive contribution to rural inhabitants’ well-being in and around Thulamela Local Municipality in Vhembe District of South Africa. Information on the uses of invasive alien plant species were obtained in 2010 through interviews with local inhabitants and traditional healers. Twenty one plant species, from 15 families, were found to be utilized by rural inhabitants. These species are important sources of food and medicine, provide firewood, and are of aesthetic value. They have become alternative sources of utilization, where the indigenous vegetation has been decimated by overexploitation. This study postulates that their extensive use, under careful management, could form part of a strategy for social upliftment and environmental management in poor rural municipalities.
Open Access
Medicinal utilization of exotic plants by Bapedi traditional healers to treat human ailments in Limpopo province, South Africa
(Elsevier Ireland Ltd., 2012-10-13) Semenya, Sebua S.; Potgieter, Martin; Tshisikhawe, Milingoni P.; Shava, Soul; Maroyi, Alfred
Ethnopharmacological relevance: Most exotic plants are usually labelled as alien invasives and targeted for eradication. However, some of these exotic plants play an important role in the traditional primary healthcare sector of the Bapedi culture in the Limpopo Province of South Africa. The medicinal uses of most of these species have neither been documented nor their biological activity evaluated. Aim of the study: To make an inventory of exotic species employed by Bapedi traditional healers to treat different human ailments in the Limpopo Province, South Africa. Materials and methods: Semi-structured interviews, observation and guided field walks with 52 traditional healers were employed to obtain ethnobotanical data during first half of 2011 on the use of exotic plant species by Bapedi healers to treat human ailments. Based on ethnobotanical information provided by these healers, specimens were collected, numbered, pressed, and dried for identification. Results: A total of 35 exotics species belonging to 21 families and 34 genera, mostly from the Fabaceae and Solanaceae (11.4% for each), Apocynaceae and Asteraceae (8.5% for each) were used by Bapedi healers to treat 20 human ailments. Trees (45.7%) and herbs (37.1%) are the primary source of medicinal plants. Species most frequently reported were used for the treatment of hypertension (35%), diabetes mellitus, erectile dysfunction and gonorrhoea (25% for each). The highest consensus from individual accounts of the traditional healers on the use of exotic plant remedies in this study was noted for the three ailments. These were for Catharanthus roseus (gonorrhoea, 60%), Punica granatum (diarrhoea, 38.4%) and Ricinus communis (sores, 21.5%). Of the 35 exotic plant species recorded, 34.2% are regulated by the Conservation of Agricultural Resources Act (1983) (CARA) No. 43 of 1983 either as worst weeds or invaders. Conclusion: The present study demonstrated that exotic plant species play an important part as medicinal remedies employed by Bapedi healers to treat different human diseases in the Limpopo Province. The use of these species as alternative sources of medicinal remedies could alleviate harvesting pressure of wild indigenous plants, thereby enhance biodiversity’s region. However, there is a need to formulate an appropriate policy to retain some of the useful medicinal exotics (listed under CARA No. 43 of 1983) within the environment before their medicinal value vanishes as they are eradicated through management strategies adopted by the South African government.
Open Access
An evaluation of the extent and threat of bark harvesting of medicinal plant species in the Venda Region, Limpopo Province, South Africa
(2012-11-11) Tshisikhawe, M. P.; van Rooyen, M. W.; Bhat, R. B.
The medicinal flora of the Venda region consists of a variety of species, which may potentially provide therapeutic agents to treat different diseases. Bark use for medicinal purposes has been reported for approximately 30% of the woody species (153 species) in the Venda region in southern Africa. However, only 58 plant species are commonly harvested for the medicinal properties in their bark and found in muthi shops in the region. These 58 species were scored for the possible threat of bark harvesting to the plant survival. Ethnobotanical studies indicate that the growing trade in indigenous medicinal plants in South Africa is posing a threat to the conservation and preservation of many plant species. Apart from pharmaceutical companies, trade in medicinal plants has become a way of making a living for some people. This study investigated the pattern of trade in medicinal plants by local markets in the Venda region, Limpopo Province, South Africa. Indications are that bark harvesting may threaten some of the plant species.
Open Access
Population biology of Brackenridgea zanguebarica in the presence of harvesting
(Academica Journals, 2012-12-03) Tshisikhawe, Milingoni P.; Van Rooyen, Margaretha W.
Population biology studies play a major role in understanding the ecology of our highly utilized natural resources. Intense and frequent harvesting of bark from species with a high market demand often result in ring-barking of trees. The trees subsequently die, and the species becomes rare over time. Brackenridgea zanguebarica Oliv. is a species in demand not only because of its medicinal value but also because it is highly regarded for its magical value. The species has a limited distribution and is found only at Thengwe in the whole of South Africa. The population structure of the species was investigated and the response of the species to harvesting pressure evaluated in order to gain an understanding of its survival strategies. In spite of the high demand for the species it seems to be surviving the harvesting pressure. B. zanguebarica showed a healthy population structure with lots of seedlings. The adult individuals showed a very high degree of bark regeneration as a response to bark removal from medicine men. The inverse J-shaped curve showed that the population is healthy although sharp decreases between stem diameter size classes were observed. Fewer older individuals have healthy crown covers since crown health status tends to decrease with increase in stem diameter. It is therefore important to monitor the diameter size classes that are being impacted negatively by medicinal bark harvesting for the population to remain viable at all times.
Open Access
Analysis of the solar radiation data and the determination of regression coeffients for Vhembe Region, Limpopo Province
(2012-12-11) Mulaudzi, Tshimangadzo Sophie; Sankaran, V.; Lysko, M. D.
Open Access
Genetic characterization of human immunodeficiency virus from Northern South Africa
(2012-12-19) Iweriebor, Benson Chuks; Bessong, Pascal Obong; Mphahlele, Jeffrey; Moyo, Sylvester Rodgers
Open Access
Mathematical modelling of transmission and control of malaria
(2012-12-19) Mulaudzi, Matodzi Stanley; Garira, Winston
Open Access
Computational study of the molecules of selected acylated phloroglucinols in vacuo and in solution
(2012-12-19) Kabanda, Mwombeki Mwadham; Mammino, Liliana; Ghio, Caterina
Open Access
How fast can you climb a mountain? climate change, ant assemblages and a centre of endemism
(2012-12-19) Munyai, Thinandavha Caswell; Foord, S. H.; Baxter, R. M.
Open Access
A comparative evaluation of rural development programmes in the Thulamela Municipality : a case study of Sidou and Malavuwe Villages
(2013) Musiwalo, Takalani Enos; Nelwamondo, T. M.; Mudau, N. V.
The focus of the study is on the comparative assessment of Rural Development Programmes between Sidou and Malavuwe Village within Ward 22 of the Thulamela Municipality. The study aims to investigate the gap that exists between effective programme implementation and less effective programme implementation in rural areas. To achieve this, the study uses Malavuwe Village as a control village and Sidou Village as an experiment village. The study found that there was a discrepancy in service delivery between the two villages; more services were delivered effectively at Malavuwe than at Sidou Village. The study further investigates the causes of this discrepancy in service delivery between the two villages and also suggests feasible approaches that can be employed by the Thulamela Municipality to enhance programme implementation and service delivery within the study area. The study found that Sidou Village lacked community services such as clinics, high schools, community halls, sporting facilities and income generating community projects. On the contrary, Malavuwe Village had most community services. Based on the findings of the study, it is recommended that the Thulamela Municipality should ensure thorough provision of services and encourage community participation through consultation and partnership at Sidou Village. Such an approach will be bottom-up and will encourage community members at Sidou Village to be actively involved in the prioritisation and implementation of vital services, thus raising the socioeconomic conditions and infrastructure development in the village
Open Access
Population biology of Elaeodendron transvaalense Jacq. in the presence of harvesting
(Fyton, 2013-01-12) Tshisikhawe, M. P.; Van Rooyen, M. W.
Elaeodendron transvaalense Jacq. is one of the medicinal plant species commonly used by people in the Venda region. The species is known to treat a variety of diseases. It is widely used and important to traditional healers. Because of this, it found its way into the muthi markets, and it is among the seven most commonly traded plant species in the Venda region. This study investigated the impact of bark harvesting on the population structure of this species. The study revealed that although the level of bark harvesting is high, the species is able to resist that stress since it is a fine-grained species. The population also showed the ability to regenerate as it exhibited an inverse J-shaped curve. The crown health status was generally good although some individuals, contributing 9% of the sample, had dead crowns, which are a cause for concern. A linear relationship was noticed between areas harvested and stem circumference, which is understandable considering the large surface area of harvestable bark on bigger individuals.
Open Access
An evaluation of environmental sustainability of land reform in Zimbabwe : a case study of Chirumanzu District, Midlands Province
(2013-02-26) Kori, Edmore; Musyoki, A.; Nethengwe, N. S.